Yep! And to add to #1 I've seen people choose poorly and then write really bad code to make-up the velocity lost by the poor choice, and then see this as a virt

Yep! And to add to #1 I've seen people choose poorly and then write really bad code to make-up the velocity lost by the poor choice, and then see this as a virtue (eek!). A good choice should allow you to write fairly decent code, as it's natural to do so exactly because you chose a tech stack that fits the problem space! And if you're not quite sure what the problem space is, that means choosing a flexible tech stack and avoiding giant and costly assumptions.